Conventional auto windshield wipers operating under the restriction of a small action pressure cannot completely eliminate all of the rain drops from a windshield. Under such circumstances, the driver's vision on a rainy day is bound to be somewhat adversely affected. Therefore, a pressure increasing accessory A has been provided in an attempt to solve this problem, as shown in FIGS. 7, 8. This prior art system includes three inclined wind pressure blades C connected to a resilient clip B and installed to the operating arm E of the wiper D. In this way, by providing three wind pressure blades C which are impinged by the "wind" generated by the car's movement, the wiping effect of wiper D does get improved by an increased action pressure. But its function leaves room for improvement.